Enhanced mobile station positioning in a wireless communication network

ABSTRACT

An approach to facilitating positioning operations or other designated tasks performed by mobile stations within a wireless communication network enables individual mobile stations to request “free” or idle time if the mobile station&#39;s current operations do not provide sufficient background time to perform the required task. For example, the mobile station might be commanded to perform a positioning computation within a required time limit. If its background processing time is insufficient, the mobile station requests additional idle time from the network, which, if allocated by the network, is used by the mobile station to complete the required processing task. In an exemplary application, a GPRS-based network allocates additional “idle” blocks into the time-multiplexed multiframe structures supporting packet data communications with the mobile station. Here, the mobile station indicates the idle time needed, and the network determines how best to distribute the required idle blocks over one or more forthcoming multiframes.

BACKGROUND OF THE INVENTION

The present invention generally applies to wireless communicationsystems, and particularly applies to allocating time to mobile stationsfor the performance of processing tasks at the mobile stations.

As mobile communication devices continue their move toward completeintegration into the framework of our daily lives, their range of usescontinues expanding. For example, location-based services represent onearea of rapidly increasing activity. In its broadest sense, the notionof location-dependent services entails tracking or otherwise identifyingthe locations of one or more users, perhaps at specific times, andmaking location-specific information available to them.

Such services might operate as “push” facilities where information isautomatically delivered to a user's mobile communication device uponentering a given geographic zone or area, or might operate as “pull”services where the user solicits location-specific information from thesupporting network. In either instance, the user generally gives priorapproval for the use of his or her mobile communication device inlocation-based services. Emergency services location operationsgenerally represent an exception to this prior approval scheme.

In any case, a given wireless communication network might offer a rangeof different location-based services, perhaps available based on varyingsubscription costs. Further flexibility is gained by giving third-partylocation services providers controlled access to the wirelesscommunication network. In this manner, entities other than the networkservice provider can offer network subscribers selected location-basedservices, often doing so based on formal agreements between thethird-party provider, the network operator, and the individualsubscribers.

Effective, accurate, and timely location measurement entails overcomingmany challenges. Different types of wireless networks use differingmobile positioning schemes. Positioning schemes range from therelatively course approach wherein a mobile's position is reported onlyto the “serving cell,” to more sophisticated approaches based on GlobalPositioning System (GPS) information, which can yield mobile stationposition accuracy on the order of ten meters. Even without GPS, wirelessnetworks using time-of-arrival techniques provide measurement accuraciesof one hundred meters or less.

In general, the various wireless network implementations each supportseveral approaches to mobile station positioning. For example, thetechnical specification TS 43.059 specifies standard LoCation Services(LCS) methods for networks based on the GSM-EDGE Radio Access Network(GERAN) standards, where GSM represents Global System for MobileCommunication, and EDGE represents Enhanced Data Rates through GlobalEvolution. As those skilled in the art will recognize, EDGE specifiesrelatively sophisticated modulation techniques that may be used forhigher data rate communication within the radio frequency spectrumallocated for GSM systems. GERAN systems can employ cell coverage basedpositioning methods, Enhanced Observed Time Difference (E-OTD)positioning methods, and/or GPS based positioning methods.

Similarly, the developing standards falling under the umbrella ofUniversal Terrestrial Radio Access Network (UTRAN) allow for variouspositioning approaches. The technical specification TS 25.305 UTRANStage 2 identifies supported locating methods as including cell coveragebased positioning methods, Observed Time Difference of Arrival (OTDOA)positioning methods, and GPS based positioning methods.

Common to many of these schemes, and true across these and other networktypes, most positioning approaches depend on the individual mobilestations to support at least some of the position-related operationsnecessary to locate the mobile station to the desired accuracy withinthe wireless network. That is, most positioning approaches require themobile station to perform at least some of the measurements and/orcomputations associated with location determination.

This reliance on the mobile station taxes its ability to, in some cases,compute and provide timely position-related information. For example,General Packet Radio Service (GPRS) in GERAN provides relativelyhigh-speed packet data services to GPRS-capable mobile stations. Themaximum data rate depends on a number of parameters, including thecapabilities of the mobile station itself. In general, however, thehigher the data rate, the less “free” time available to the mobilestation. That is, under packet data service operation, the mobilestation's time is increasingly dedicated to transmit and/or receiveoperations with increasing data rate.

Indeed, operating scenarios within the context of GPRS and other networktypes can arise where the mobile station is engaged in datacommunication services to the extent that it lacks enough freeprocessing time to perform required position-related operations.Ideally, the wireless communication network would include provisionsthat, where appropriate, allocate the time needed by the mobile stationfor position-related operations without disrupting ongoingcommunication.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a method and apparatus permitting amobile station engaged in active communication or otherwise operating ina mode with insufficient background or idle time to request additionalidle time to perform required processing tasks, such positioningoperations as in support of LoCation Services (LCS) within a wirelesscommunication network. While the idea is applicable to a variety ofwireless communication network types, application of the presentinvention to General Packet Radio Services (GPRS) networks represents anexemplary use.

While LCS implementations vary across network types and by equipmentvendor, such operations commonly require mobile stations to perform atleast a portion of the required positioning operations. In certain modesof operation, while engaged in high data rate communication, forexample, there may be insufficient background processing time availableat the mobile station to perform a designated task, such as a requiredpositioning operation, within a defined time limit. Under thesecircumstances, the mobile station requests additional “idle” or freetime from the supporting network, which, if granted by the network,allows the mobile station to timely complete the desired positioningoperations by performing the needed processing during the forthcomingtimes designated by the network as idle time responsive to the requestfrom the mobile station.

In one embodiment applicable to GPRS networks, mobile stations operatingin packet data mode request additional “idle” blocks or frames from thenetwork, if required to perform a positioning operation more quicklythan the default number of idle frames permits. That is, a given mobilestation might receive a request indicating a desired positioningoperation and the desired time for completing that operation, and thendetermine that the amount of background processing time currentlyavailable to it is insufficient. If so, the mobile station transmits arequest for the number of idle frames it needs to timely complete thepositioning operation.

Upon receiving this request, the network determines whether, forexample, its ongoing user scheduling operations will permit it to honorthe request for additional idle time. If not, the network sends aresponse message indicating denial of the request. In that instance, themobile station might respond with an error message indicating that itcannot perform the requested positioning operation within the desiredtime.

If the request is granted, the network generally determines the specificallocation of additional idle time. That is, the network determines howbest to allocate additional idle frames in one or more forthcoming TDMAframes, such that the mobile station receives the requested amount ofadditional idle time. By interleaving the additional idle time intosubsequent sets of active TDMA frames, the network enables the mobilestation to perform the requested positioning operation withoutdisrupting ongoing communication.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an exemplary GPRS/GSM wireless communicationnetwork in accordance with the present invention.

FIG. 2 is a diagram of the 52-multiframe structure defining therepeating TDMA frames used in packet data communication between a mobilestation and wireless networks in GPRS.

FIG. 3 is a diagram of exemplary receive (RX) and transmit (TX) TDMAtimeslot/frame structures used in TDMA-based wireless communication.

FIG. 4 is a diagram of an exemplary request/response signal flow diagramillustrating the request for and allocation of additional idleprocessing time for a mobile station.

FIGS. 5A and 5B are exemplary logic flow diagrams illustrating therequest for and response to the grant of additional idle processing timeat a mobile station.

FIG. 6 is an exemplary logic flow diagram illustrating the networkreceipt of and the response to a request for additional idle processingtime from a mobile station.

FIG. 7 is a diagram of an exemplary mobile station and network.

DETAILED DESCRIPTION OF THE INVENTION

While various embodiments of the present invention find applicabilityacross a range of wireless communication network types, many of thefollowing exemplary details focus on GPRS networks because that focusgives a clear context to the examples. However, it should be understoodthat the techniques described herein are not limited to applicationwithin GPRS networks.

With the above comments in mind, FIG. 1 illustrates an exemplary butsimplified wireless communication network 10, configured here as a GPRSnetwork. The exemplary network 10 comprises a radio access network (RAN)12 communicatively linked with a core network (CN) 14. In this exemplaryembodiment, the RAN 12 is configured as a GSM EDGE Radio Access Network,or GERAN, and provides communication support for a plurality of mobilestations 16, with only three shown (16-1 through 16-3) for simplicity.At least one of the mobile stations 16 operates as a GPRS terminal, andthus supports packet data communication in accordance with GPRS-basedpacket services.

Here, the RAN 12 includes systems supporting communication and locationservices functions (LCS functions). More specifically, the RAN 12comprises a base station system (BSS) 20, including a base stationcontroller (BSC) 22 and one or more base station transceivers (BTSs) 24.The BSC 20 may include LCS systems, such as a serving mobile locationcenter (SMLC) 26, and a cell broadcast center (CBC) 28. Alternatively,the SMLC 26 and CBC 28 are affiliated with the BSS 20, but notnecessarily included within the BSC 22, which configuration also isshown in the diagram. RAN 12 may further include one or more locationmeasurement units (LMUs), here LMUs 30 and 32. As suggested by thenomenclature, the LMUs 30 and 32 support LCS operations (positioningoperations) by performing certain measurements and computations.

The CN 14 comprises a serving GPRS support node (SGSN) 40, a gatewaymobile location center (GMLC) 42, and a home location register (HLR) 44.In general terms, the SGSN 40 includes functionality supporting mobilestation subscription authorization, and managing positioning requestsassociated with LCS. Typically, the LCS functions of the SGSN 40 relateto charging and billing, LCS co-ordination, location request,authorization and operation of the LCS services within the network 10.

The GMLC 42 includes functionality supporting LCS, and it should beunderstood that, as with the other network entities depicted, theremight be more than one GMLC within the network 10. In any case, the GMLC42 is the first node accessed by an external LCS client, e.g., athird-party service providing offering network subscribers one or moreLCS-based services. In support of LCS operations, the GMLC 42 mayrequest routing information from the HLR 44, and after performingregistration authorization, it sends positioning requests to variousother network entities, such as the SGSN 40, or a mobile switchingcenter (MSC) not shown. Generally, regardless of the particulararrangement involved, the GMLC 42 receives final location estimates fromthe corresponding entity or entities.

Finally, the HLR 44 generally includes LCS subscription data and routinginformation for the various subscribers supported by the network 10,e.g., the users of mobile stations 16. Under roaming conditions, one ofthe mobile stations 16 might be a visitor to network 10, and itscorresponding HLR might be located in another wireless network, e.g., inanother public land mobile network (PLMN).

Regardless of network type, i.e., GPRS, IS-136 TDMA, etc., LCS involvesa wide range of operations, and depends on varying implementationdetails, but in general LCS involves determining on demand the locationof one or more mobile stations 16 operating within the service area ofnetwork 10. Apart from the obvious benefit for facilitating emergencyassistance to subscribers, the ability to locate mobile stations 16allows the network service provider and various third-party providers tooffer a range of location-based services.

For example, third-party service providers might interface with thenetwork 10 to provide location-based advertising to network subscribers.That is, a subscriber nearby a given business might receive notificationof an on-going sale on his or her mobile station 16. Further, a givensubscriber might pay a service premium to receive location-sensitivelocal information, such as information on the nearest gas station, thenearest Italian restaurant, etc. In this context, the network 10receives a request from an external system (i.e., a third-party serviceprovider) to report the current location of a particular mobile station16.

While these commercial location applications vary, individualsubscribers generally contract in advance either through the networkservice provider, or the appropriate third-party provider for suchservices. That is, the network 10 generally will not provide LCS-basedadvertising or notifications to subscribers that have not explicitlyindicated a desire to receive such services. Of course, even subscribersthat do not participate in the commercial side of LCS benefit from it interms of emergency location support, and in terms of the role played byLCS in network operations, such as location assisted handoff betweenBTSs 24.

In exemplary instances, the CN 14 requests a location estimate of atarget mobile station 16, i.e., requests a location estimate for aspecific one of the active mobile stations 16. In general, the locationrequest contains sufficient information to enable location of the targetmobile station 16 in accordance with any required quality of service(QoS) constraints based on any positioning method supported by thenetwork 10. As an example, the CN 14 might request the currentgeographic coordinates of the target mobile station 16.

As was noted earlier, the network 10 might employ any one or severaldifferent LCS technologies, each offering differing complexity, networkoverhead, and location accuracy. Approaches to mobile stationpositioning include GPS, E-OTD and other variations on signaltime-of-arrival observations. While these various approaches offerdiffering degrees of accuracy, i.e., positioning resolution, eachrequires a certain level of processing or computational support from thetarget mobile station 16.

For example, with E-OTD, the target mobile station 16 might measure thetiming differences between multiple BTSs 24. For example, knowing thedelays between three or more neighboring BTSs 24 relative to the targetmobile station 16 permits relatively accurate (sub 100 meter)positioning of the target mobile station 16. Thus, in this scenario, theCN 14 generates a location request, which is transmitted to the targetmobile station 16 by the RAN 14. Generally, the request identifies thedesired or needed positioning operation to be performed by the targetmobile station 16, and further identifies the desired time forresponding to the positioning request. As an example in the GPRScontext, the network 10 sends a “RRLP Measure Position Request” messageto the target mobile station 16, where RRLP represents Radio ResourceLCS Protocol, which is covered extensively in the 3^(rd) GenerationPartnership Project (3GPP) technical specification 3GPP TS 44.031V5.1.0, entitled “Radio Resource LCS Protocol,” and released on 2001December.

Thus, the target mobile station 16 generally receives a positioningrequest that indicates to the mobile station 16 the needed positioningoperation and a defined time for performing that operation. Thisinformation allows the mobile station 16 to determine whether itscurrent operating mode provides sufficient background or idle processingtime to perform the needed positioning operation within the definedtime.

To better understand how operating mode influences available backgroundprocessing time, FIG. 2 illustrates the TDMA frame structure used bymobile stations 16 engaged in packet data calls with the network 10.That is, FIG. 2 illustrates the frame structure of the packet datachannel (PDCH) defined for packet data communications within GPRSnetworks. GPRS multiplexes several users onto the same receive andtransmit (RX/TX) frequency pair by organizing the radio resources inaccordance with a TDMA scheme defining a repeating multiframe structure.

Specifically, packet data communications use a 52-multiframe structurecomprising twelve radio blocks (B0–B11), with one idle frame interposedbetween groups of three radio blocks for a total of four idle frames per52-multiframe. FIG. 3 illustrates the structure of receive and transmitframes. One frame comprises eight time slots, TS0 through TS7.Generally, a portion of TS0 on one channel in each cell is used as thesynchronization channel, SCH. Thus, each 52-multiframe comprises 52frames, with eight time slots per frame. Each user, i.e., a specific oneof the mobile stations 16, is assigned one or more receive (RX) timeslots and one or more corresponding transmit (TX) time slots. Forexample, if a user is assigned RX time slot three, which is illustratedin the diagram, that same user is usually assigned TX time slot three.

As noted from the diagram, the TX time slots may be shifted relative tothe RX time slots to avoid mobile stations 16 having to simultaneouslyreceive and transmit. That is, the RX and TX time slots are shiftedrelative to one another so like numbered RX and TX time slots are notcoincident in time.

Understanding the time slot/multiframe structure in the context ofGPRS-based packet data communication leads to an understanding of thelimits on available background processing time at the mobile stations16. For example, certain types of mobile stations 16 achieve higherpacket data rates by using more time slots per frame. Such mobilestations are referred to as “multislot class” terminals, meaning thatterminals of that type have the capability to receive and transmit on agreater number of time slots within the repeating TDMA frames.

Essentially, the mobile stations 16 have only limited background or idleprocessing time. Here, background processing or idle time refers to theintermittent periods between active radio reception or transmissionprocessing, and the processing directly attendant to those tasks.Generally, in the context of GPRS, background processing opportunitiesarise between receive (RX) and transmit (TX) bursts, and during the idleframes within the repeating 52-multiframe structures. Such limitedbackground processing time might prevent a target mobile station 16 fromperforming a requested positioning operation within the indicated timelimits.

An exemplary approach to gaining additional, temporary background oridle processing time allows the target mobile station 16 to determinehow much additional idle time it needs to perform the needed positioningoperation, and then request that additional idle time from the network10. If the network 10 grants the request, it communicates back to thetarget mobile station 16 the specific times within the forthcoming TDMAframes that the target mobile station 16 should use for processingassociated with the needed positioning operation.

Effectively, the network 10 must determine, if it grants the request,how best to interleave idle time with active communication time, andmust insure that it does not attempt to use the time granted forcommunication activities as regards the requesting mobile station 16.That is, if the network 10 indicates that certain future times, e.g.,time slots or frames, will be idle as regards the requesting mobilestation 16, it must observe that restriction to avoid scheduling datatransmission/reception to or from that mobile station 16 during thosetimes.

In general terms, the target mobile station 16 determines how muchprocessing time is required to complete the requested positioningoperation and, if currently available background processing time isinsufficient, requests additional idle time from the network. It mayframe this request in terms of cumulative time required to perform theneeded positioning operations, or the target mobile station 16 mightexpress the needed time in terms of pre-defined time units. With thislatter approach, the target mobile station 16 might, in exemplaryembodiments, construct its request in terms of the number of additionalidle frames needed to complete the requested positioning operation.

FIG. 4 illustrates an exemplary approach in simplified terms, and in thecontext of GPRS. The target mobile station 16 recognizes that it needsmore idle time to complete a requested positioning operation within therequired time. Thus, it forms a “Packet Idle Block Request” message,which might include, but is not limited to, the following items: atemporary logical link identifier (TLLI) which identifies the mobilestation 16 on a temporary basis and which values allows the message tobe sent during discontinuous reception mode (DRX); the total number ofidle frames required; and the number of 52-multiframes over which themobile station 16 desires the requested idle frames to be distributed.

Upon receiving the request from the target mobile station 16, thenetwork 10 generates a “Packet Idle Block Response” message, which ittransmits to the requesting mobile station 16. An exemplary responsemessage might include, but is not limited to the following items: theTLLI; a result indicator (i.e., request granted or denied); the numberof forthcoming 52-multiframes over which the requested idle block grantwill remain valid; a listing of the idle blocks (or frames) within theidentified 52-multiframes which are designated as additional idle time.For example, the network 10 might provide a listing from the definedradio blocks B0–B11 that are granted as idle blocks in the specifiednumber of forthcoming 52-multiframes. That is, the response message canindicate which radio blocks are temporarily re-designated as idle blocksfor use by the requesting mobile station 16.

FIGS. 5A and 5B illustrate exemplary operations at the target mobilestation 16. Initially, the mobile station 16 operates in a “normalstate” with the default amount of idle processing time available (Step100). At some point, the mobile station 16 receives a positioningrequest message, requesting the mobile station 16 to perform one or morepositioning operations within a stipulated time. For example, thenetwork 10 might ask the mobile station 16 to determine its location towithin 100 meters within two seconds. As noted earlier, the mobilestation/network might employ different locating technology, such asA-GPS and/or E-OTD. In any case, the request defines the neededpositioning function(s) and typically provides the mobile station 16with time limits for carrying out those functions.

For GPRS applications, the mobile station 16 determines if it isoperating in packet transfer mode (Step 104). If not, the mobile stationmay be in a packet idle mode, or in a voice mode. In either case, themobile station 16 likely has sufficient background or idle time toperform the needed positioning operation. Such background time isavailable since voice under GSM generally uses a single RX and TX timeslot in each frame, leaving considerable intra-frame processing timebetween receive and transmit operations. Thus, if it is not in packettransfer mode, the mobile station 16 simply performs the requestedoperations (Step 106), returns the results to the network 10 (Step 108),and continues operation in normal mode (Step 110).

However, if the mobile station 16 is in packet transfer mode, itdetermines whether that mode allows it sufficient background processingtime to perform the needed operations within the stipulated time limits(Step 112). For example, packet transfer mode using single RX/TX timeslots per frame might allow for positioning processing absent a requestfor additional time, while multislot class operation may require arequest for additional time. If the mobile station 16 determines thatits current operating mode requires it to request additional idle time,it formulates that request and transmits it to the network 10 (Step114).

Turning now to FIG. 5B, and moving from Point “A” in the flow of FIG.5A, the mobile station 16 waits for a response to its request foradditional idle time (Step 116). It waits within prescribed time limits,or timely receives a response message, and then the mobile station 16breaks from the waiting loop (Step 118). At this point, the mobilestation 16 determines whether the request was granted, and, if so,whether the granted additional idle time is sufficient for its needs(Step 120). Ordinarily, the network 10 meets the mobile station's idletime needs if it grants the request at all, but there might still beinstances where it is beneficial for the mobile station 16 to verifythat the additional idle time allocated by the network 10 actually meetsits processing needs.

In any case, if the request is granted and sufficient additional idletime has been granted, the mobile station 16 performs the neededpositioning operations using the allocated time (Step 122). Note thatthe mobile station 16 might formulate the request for additional idletime based on the difference between currently available idle time andthe needed amount, in which case it should be understood that the mobilestation 16 might use the default idle time that would have existedabsent its explicit request plus the newly granted additional idle time.Further, note that the response from the network 10 generally identifiesthe specific frames within one or more of the upcoming 52-multiframesthat are newly designated as idle frames for use by the mobile station16. By maintaining synchronization with the time slot/frame timing ofthe network 10, the mobile station 16 synchronizes its positioningoperations to coincide precisely with the allocated times. Thismobile-to-network synchronization is an explicit requirement inGSM/GPRS, as it is in most other types of communication networks, and iswell understood by those skilled in the art.

Upon completion of the requested positioning operations, the mobilestation 16 returns the results to the network 10 (Step 124), and returnsto the normal state (Step 126). Returning to the normal state hereimplies a return to the default allocation of idle time.

If the request was not granted, or if the request granted insufficientadditional idle time (Step 120), the mobile station 16 may generateappropriate error information or respond in modified fashion (Step 128).For example, if the mobile station 16 is not granted sufficient time tocomply with the request, it may return an error message, or performabbreviated processing and return a less accurate or less completeresult, or may perform full processing but return the result at a timelater than specified by the request (Step 130). As noted earlier, thiserror message might be formed as an RRLP error message in the context ofGPRS networks.

While FIGS. 5A and 5B illustrate exemplary mobile station operations,FIG. 6 illustrates exemplary, corresponding network operations.Processing begins with the network 10 operating with the default ornormal amount of idle time (Step 140). At some point, the network 10receives a request for additional idle time from the target mobile 16(Step 142). This request generally comes in response to the network 10transmitting a positioning request to the target mobile station 16.

Upon receiving the request for additional idle time, the network 10evaluates the request to determine whether and how the request can begranted (Step 144). As those skilled in the art will appreciate, theongoing scheduling of communication services for the large number ofusers typically supported the BSS 20 requires relatively sophisticatedscheduling algorithms that determine which user or users are served atany given time, and further determine the optimum or best order ofservice over the forthcoming service intervals.

In general, user scheduling requires the BSS 20 to make repeated sets ofpotentially complex calculations representing the relative advantagesand disadvantages of serving one user to the exclusion of the others atsucceeding points in time. While a detailed treatment of schedulingalgorithms is not needed to understand the present invention, exemplaryembodiments of the present invention generally include consideration ofuser scheduling priorities when determining whether to grant request foradditional idle time.

If the network 10 denies the request (Step 146), it forms its requestresponse message to indicate such denial (Step 148). Network 10 thensends this response to the requesting mobile station 16 (Step 150), andcontinues with normal operations (Step 152). However, if the request isgranted, the network 10 determines the specific allocation of idle timein one or more forthcoming windows of time (Step 154). For example, inthe context of GPRS, the network 10 determines which radio blocks inwhich forthcoming 52-multiframes will be newly designated as idle blocksas regards the requesting mobile station 16. For example, the mobilestation 16 might request sixteen idle frames within a defined window oftime, and the network 10 determines whether to designate all twelveradio blocks in a forthcoming 52-multiframe and a remaining four blocksin a succeeding 52-multiframe as idle blocks for the mobile station 16.Alternatively, the network 10 might adopt some other distribution schemefor the needed idle blocks over some number of forthcoming52-multiframes.

In fact, preserving some radio blocks within a given 52-multiframe asactive communication blocks offers some advantages. For example, by notsetting aside an entire 52-multiframe as idle time, the networkpreserves ongoing communication with the requesting mobile station 16,rather than completely disrupting communication during one or more52-multiframes. Thus, the mobile station 16 requests a certain amount ofidle time, specified in terms of frames, blocks, or using some otheragreed-upon time indicator, and the network 10 determines how toallocate the needed time. Since the network 10 generally knows thestipulated time limit in which the mobile station 16 is expected tocomplete the needed positioning operation, it generally knows the extentto which it can distribute additional idle time into future52-multiframes.

Regardless of the particular approach taken, if the network 10 grantsthe request, it forms its response message to include indications of thegrant, and the particular designation or allocation of idle time to beused by the mobile station 16 (Step 156). The network 10 then sends thisresponse message to the mobile station 16 (Step 158), and takes measuresto observe the allocated idle times. Specifically, this means thatnetwork 10 does not schedule communication activities (RX or TX) for themobile station 16 during the times it has identified as additional idletime (Step 160).

Once the period over which the allocated additional idle time spans haspassed, the network 10 automatically returns to the default idle timestructure consistent with the mobile station's operating mode. Thisapproach minimizes the processing and messaging overhead betweenrequesting mobile stations 16 and the network 10. That is, by having thenetwork 10 automatically resume normal idle time allocations, there isno need to explicitly signal or request the end to additional idle timeallocations.

While the above mobile/network logic is subject to much variation, itrepresents an exemplary approach to implementing at least some of theideas of the present invention. Likewise, FIG. 7 illustrates exemplarynetwork and mobile station details for supporting the above exemplaryapproach that are themselves subject to much variation. In FIG. 7, theBSC 22 comprises a processing system or systems 50, including ascheduler algorithm 52, and associated with supporting memory 54. Here,memory 54 is understood to potentially include dynamic and staticprogram memory, as well as non-volatile memory, including, but notlimited to, FLASH, disk or tape.

In an exemplary approach, the algorithm 52 looks at current schedulingoperations involving those users (i.e., mobile stations 16) supported byBTS 24, and bases its granting or denying of incoming requests foradditional idle time based on its ability to integrate those requestswith ongoing scheduling operations. In general, scheduling algorithm 52represents just one of many applications or program subprocesses runningon processing system 50.

The exemplary mobile station 16 comprises an antenna 60 coupled to areceiver 62 and to a transmitter 64 through a switch 66. Note that theswitch 66 might further include duplexer-type filters or other filteringcircuits for isolating RX and TX signals during certain modes ofoperation. Regardless, the exemplary mobile station 16 further comprisesa baseband processor 68, a system processor 70 and associated memory 72,along with a keyboard 74, a display 76, a microphone 78, and a speaker80, which collectively interface to the system processor 70 viainput/output (I/O) circuits 82.

The baseband processor 68 might comprise one or more digital signalprocessors (DSPs), custom circuits such as Application SpecificIntegrated Circuits (ASICs) or Field Programmable Gate Arrays (FPGAs),or some combination thereof. In any case, the baseband processor 68generally plays a primary role in supporting communication operations,such as by providing signal demodulation and decoding on the receiveside, as well as signal encoding and transmission modulation on thetransmit side. Baseband processor 68 may or may not include programlogic to implement the present invention as illustrated in FIGS. 5A and5B, for example. If not, that functionality might be supported in thesystem processor 70, in which case the required functionality might beimplemented as stored program logic in memory 72.

In that scenario, the baseband processor 68 signals the system processor70 regarding the positioning request, allowing the system processor 70to determine whether or not a request for additional idle time should betransmitted to the network 10. Thus, the system processor 70 might forma request message, which it then relays to the baseband processor 68 forthe appropriate encoding and modulation operations, after which it istransmitted via modulated RF carrier to the network 10.

One aspect not discussed yet concerns the use of so called Uplink StateFlags (USFs), which finds use in GPRS systems, and may have equivalentindicators in other types of networks. These USFs are sent by thenetwork 10 to mobile stations 16 in the downlink blocks, and are usedfor dynamic and extended dynamic allocation of uplink data transfer.(Note that fixed uplink transfer allocations are unaffected.) The USFstell the respective mobile stations 16 whether they are, on anindividual basis, scheduled to send uplink data on the next TX radioblock, or, in some cases, the next four radio blocks, in TX52-multiframes from the mobile stations 16. Thus, when the network 10indicates to a targeted mobile station 16 that selected RX radio blocksare free for use as additional idle time, it also implies that thenetwork 10 will avoid using these identified blocks for updating USFinformation to that mobile station 16. In other words, the network 10must not try to use the downlink blocks identified as additional idletime for the mobile station 16 to send USF information to the mobilestation, or, in general, for any other purpose that requires mobilestation activity.

Finally, it should be understood that the above details are exemplary,and do not serve to limit the scope of the present invention. Indeed,the present invention is applicable to any wireless communication systemwhere the network and mobile stations may cooperate to selectively andtemporarily allocate additional idle processing time to selected mobilestations in furtherance of task processing at those mobile stations.With the techniques of the present invention, the network may grant ordeny such requests based on the flexibility of ongoing user schedulingoperations, and, if granted, may identify the forthcoming time or timesnewly designated as idle periods for the requesting mobile station. Thisallows the requesting mobile stations to continue operations in theircurrent mode, while still being granted sufficient time to meet othertask processing requirements.

1. A method of facilitating mobile station operations in a wirelesscommunication network, the method comprising: receiving a request at themobile station to perform a designated task; determining whether acurrent operating mode of the mobile station offers sufficient idle timeto perform the designated task within a desired time by determiningwhether available background processing time is sufficient to completethe designated task before expiration of the desired time, the availablebackground processing time being a cumulative time comprising intervalsbetween ongoing transmit and receive operations in combination withcurrently designated communication idle times; and requesting additionalidle time from the wireless communication network if sufficient idletime is not available at the mobile station.
 2. The method of claim 1,wherein the designated task comprises a positioning operation associatedwith locating the mobile station, and wherein the request identifies thepositioning operation and identifies the desired time for performing thepositioning operation.
 3. The method of claim 1, further comprisingdetermining the desired time from information included in the requestreceived at the mobile station.
 4. The method of claim 1, furthercomprising performing the designated task using the available backgroundprocessing time where the available background processing time issufficient to complete the designated task within the desired time. 5.The method of claim 1, wherein determining whether available backgroundprocessing time is sufficient for completing the designated task withinthe desired time comprises at least in part evaluating a number ofcurrently allocated idle time per TDMA multiframe.
 6. The method ofclaim 1, further comprising receiving a response message from thewireless communication network, wherein the response message indicateswhether the request from the mobile station for additional idle time isgranted.
 7. The method of claim 6, wherein, if additional idle time isgranted, the response message further indicates one or more future idletimes, and further comprising performing at least a portion of thedesignated task during the one or more future idle times.
 8. The methodof claim 7, wherein the one or more future idle times are identifiedtime blocks within repeating time-division-multiple-access (TDMA)frames, and further comprising performing the designated task during theidentified time blocks.
 9. The method of claim 1, further comprisingperforming the designated task during available idle times, and withoutrequesting additional idle time, if the current operating mode offerssufficient idle time to perform the designated task within the desiredtime.
 10. The method of claim 1, wherein the mobile station comprises aGPRS terminal and the wireless communication network comprises a GPRSnetwork, and further wherein receiving a request at the mobile stationto perform a designated task comprises receiving a location servicesrequest message defining a desired positioning operation to be performedby the mobile station.
 11. The method of claim 1, wherein the mobilestation and the wireless communication network communicate usingrepeating TDMA frames, and wherein requesting additional idle time fromthe wireless communication network if sufficient idle time is notavailable at the mobile station comprises requesting additional units ofidle time in forthcoming ones of the repeating TDMA frames.
 12. A methodof facilitating mobile station operations in a wireless communicationnetwork, the method comprising: sending a command to a GPRS terminal toperform a designated task; receiving, at a GPRS network, an idle timerequest from the GPRS terminal for one or more units of idle time withinone or more forthcoming TDMA frames used for communication between theGPRS terminal and the GPRS network, wherein the TDMA frames compriserepeating multiframes, each multiframe comprising a number ofcommunication frames and a default number of idle frames; determiningwhether to grant the idle time request; and sending a response to theGPRS terminal identifying one or more selected radio blocks in one ormore forthcoming 52-multiframes on a packet data channel (PDCH) to beused as additional idle time by the GPRS terminal for performing thedesignated task if the idle time request is granted.
 13. The method ofclaim 12, further comprising sending a response to the mobile stationindicating a request refusal if the idle time request is not granted.14. The method of claim 12, wherein determining whether to grant theidle time request comprises determining whether an acceptabledistribution of additional idle time over one or more forthcoming TDMAframes exists in consideration of ongoing user scheduling involving aplurality of mobile stations, including the GPRS terminal from which theidle time request was received.
 15. The method of claim 14, whereindetermining whether an acceptable distribution of additional idle timeover one more forthcoming TDMA frames exists comprises determiningwhether ongoing communication scheduling will permit the GPRS network toallocate the requested amount of additional idle time within a desiredtime limit.
 16. The method of claim 15, wherein the GPRS networkreceives an indication of the desired time limit as part of the idletime request message.
 17. The method of claim 16, wherein the GPRSnetwork knows a priori the desired time limit.
 18. The method of claim12, wherein sending a command to a GPRS terminal to perform a designatedtask comprises: determining that the GPRS terminal is required toperform the designated task; identifying a desired time limit forperformance of the task; and forming the command such that the commandindicates the designated task and the desired time limit.
 19. The methodof claim 12, further comprising: receiving a location request from athird party at the GPRS network for the GPRS terminal; determining arequired location accuracy and a required response time for the locationrequest; transmitting a location command to the GPRS terminal from theGPRS network as the command to perform the designated task; andreceiving the idle time request at the GPRS network from the GPRSterminal responsive to transmitting the location command.